Functional Safety in Inverter Hardware

Primary function of the inverter in an Electric or Hybrid Electric vehicle (EV/HEV) is to generate required AC voltage from high voltage battery to drive Electrical machine (EM). Being part of power-train of the vehicle, inverters (or hybrid control units (HCU)) are safety related electronic control units (ECU) due to the severity of the accidents/incidents that could result if the ECU is not functional as intended. Therefore it is necessary to develop the inverter in accordance with applicable safety standards. The standard ISO 26262 in particular addresses the complete development cycle of safety related automotive products. OEMs now mandate the strict adherence to ISO26262 standard for such ECUs. This paper describes how safety principles are realized in the hardware modules of inverter, which are responsible for the functional safety adherence.